Process for cracking petroleum oil



Dec. 2 1930. c. P. DUBBs Q I PROCESS FOR CRACKING PETROLEUM OIL Original Filed Oct. '8, 1920 Patented Dec. 2, .1930

UNITED STATES PATENT OFFICE CARBON P. DUIBBS, F WILMETTE, ILLIIIOIS, ASSIGNOR TO UNIVERSAL OIL TBODUC'IS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA V PROCESS FOR CRACKING PETROLEUM OIL Applicatipn filed October a, 1920, Serial No. 415,601. 'Renewed November 19, 1929.

This invention relates to a process for crackmg petroleum oil by means of heat and pressure, and has. as its object to permit only vapors of given end point to pass out of the still (not shown). Vapors pass out of the vapor- R ferring in detail to system. In this process, the reflux condensate from one still is returned to the next still of the series where itis retreated. Any desired number of stills may be used, although in the present instance, I have only shown three. It may. be desirable in certain cases where particularly refractory oil is being. treated-touse as many as six to eight stills.

In the drawing, the single figure is a view,

partly in vertical section and partly in side elevation, of an apparatus suitable for carrying out my process. k q

the drawing, 1 designates'a suitable turn ace support, provided with burners 2, 3 and 4.: In this furnace are mounted a series of stills 5,6 and 7 heated by the respective burners, whichstillsin the present instance areshown of the shell or cylindrical type. These stills are or may be all of the same size for the purpose-of uniformity of construction. Oil is fed to the first still 7 through pump 8, the inlet side. of

which is connected to feed line'9 and the discha'rg side todelivery line 10,1eading to the Suitable throttle valves 11 are inter posed in the lines 9 and 10. The still 7 is connected to the still 6 by liquid drawoflf line 12 and in turn the still 6 is connected ,to liquid overflow line 13; Each of these stills is pro vided with 'a liquidresidue drawofi' line 14, each pipe 14'having a suitable throttle valve space of the still 7. through vapor line 15 into the lower end of dephlegmator or reflux-condenser- 16. The upper end of the pipe 15 is provided witha spaced cap member 17 the arrangement being such as to permit the vapors to pass into the; reflux condenser but preventing the reflux condensate from falling back into the pipe 15. The reflux condensate is drawnofl' from the bottom-of the reflux' condenser '16 through/return line 18 into the drum or still6.' The vaportrap '19 is pro vided in the line 18 so as to permit the liquid to flow down throughv the pipe but preventing vapors from-flowing up through it. The

tained under a vapor pressure of 150 pounds.

- them still 6 is provided with the vapor outlet pipe 20, extending into the lower end of reflux condenser 21, which pipe 20 is provided with a spaced cap member 22 similar to member 17. Reflux condensate is drawn ofl from the bottom of dephlegmator 21' through return line 23 having :a vapor trap 24 to the still '5. The vapor space of the still 5 isprovided with a vapor outlet pipe 26 leading into the lower end of dephlegmator 27. :The dephlegmator 27 is provided with the vapor outlet pipe 28, which extends into the lower end of dephlegmator 21 and is provided with a spaced cap member 29 for the same purpose as described in connection with the pi e 15.

The upper end of re ux condenser 21 is provided with the vapor outlet pipe 30 which extends into the lower end of reflux condenser 16 and is provided with a similar spaced cap member 31. The upper endof the reflux condenser 16 is provided with the vapor outlet pipe 32 having throttle valve 33, which pipe 32 leads to condenser coil 34 seat-' ed in condenser box 35. This condenser coil 34 is connected to the upper end of receiver 36, which receiver is provided with liquid level gauge 37, pressure gauge 38, gas outlet a pipe 39 having throttle valve 40 and l1qu1d. drawofi' pipe 41 having throttle valve 42.

The operation of e process is as follows: Gas oil or fuel oil obtained from crude petroleum is fed either continuously or intei: mittently to the still 7, and there subjected to a temperature of say,.650 degs. F. and main- The vapors generated in the still 7 will pass into the reflux condenser-16.- The'1i htest vapors will pass out of this pon enser through the vapor line 32. Such vapors as :are-condensedtwill, be returned through reflux condensate pipe 18 back to the still 6. This still may be heated to a temperature of say, 7 O0 degs". F. The" vapors generated will pass into the reflux condenser 21, and the heavier portionscondensed and returned by the line 23 to the still 5. The lightest portionswill pass out through the line 30 into the r ux condenser 16 where a portion of ay be condensed and returned by the line 18 to the still 6. The .uncondensed portions will pass out through the pipe 32, The vapors which are generated in the still 5 are compelled to pass through all three reflux condensers and a portion of them will be con- .,may be maintained at a temperature of 500 degs F. and condenser 27 at a temperature of 600 degs. F. The temperatures of the reflux condensers may be controlled bypro-- viding suitable. aerial condensation or maybe a controlled by jacketing, them in awell known manner with water jackets through Wl'llCll water can be fed in such quantities as to regulate the temperature of the dephlegmator. By means. of this process, 50% or more of the oil treated may be converted, into gasoline of 400 end point, which will be collected in the receiver 36. J

The process is further advantageous in that the reflux condensates,being harder to crack than the original oil, are returned to the still of higher temperature than that from which they originally came. This will tend to reduce the formatlon of unsaturated compounds as it will not be necessary to heat the lightest oil which comes off from the still 7 to so high a temperature as might be necessary where the reflux condensate is returned to the still. i 1

I claim as my invention:

1. A process of cracking oil, consisting in passing the oil through a series of stills of successively increasing temperature, taking 01f vapors from each still, passing them to a reflux condenser individual to each still, returning the reflux condensate separated fromvapors'removed from a still of lower temperature directly to a still of higher temperature, passing the vapors which are not condensed in the reflux condenser connected to a still of higher temperature directly through the reflux condenser connected to a still of lower temperature and finally taklngofi the vapors from the reflux'condenser connected to the still of lower temperature.

2. A process for cracking hydrocarbon oil, conslsting in maintaining a bulk supply of 011 1n an enlarged zone at a cracking tem perature, in continuously passing unvaporbulk supplies of oil at cracking temperatures,

taking off vapors from the first bulk supply phes of soil.

i CARBON P. DUBBS.

ized portions of the oil from said enlarged zone to additional'enlarged zones, in which such oil accumulates in pools, in subjecting the oil in such additional enlarged zones to a higher temperature than that at which the oil 1s maintained in said first enlarged zone, in taking oil vapors from'said first enlarged zone, in subjecting such vapors to a dephlegmating action, in separately taking off vapors from said additional enlarged zones and in subjecting such vapors tosuccessive dephlegj of oil of said series, subjecting such vapors to a dephlegmating action, separately taln'ng 

